#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main() {
	cin.tie(0); ios::sync_with_stdio(false);
	int ans = 999,size;
	bool w_flag = false;
	string str;
	cin >> str;
	size = str.length();
	for (int i = 0; i < size;i++) {
		if (str[i] == 'c') {
			for (int j = i + 1;j < size; j++) {
				if (str[j] == 'w') {
					if (w_flag == false) {
						w_flag = true;
					}
					else {
						ans = min(ans, j - i + 1);
					}
				}
			}
			w_flag = false;
		}
	}
	if (ans == 999) { cout << -1 << endl; }
	else { cout << ans << endl; }
	return 0;
}